Bill of materials mistakes that eat a signed job's margin
The margin on a rooftop job is usually lost after signature, in items nobody priced. Fourteen line items that go missing, and the two clauses that protect you.
Topic
Design
Roof capture, shading analysis, stringing, inverter sizing and layout decisions that determine whether a rooftop system performs as quoted.
New CEA standards land in April 2027. Check your BOM
The CEA notified amended technical standards in July 2026, effective April 2027: 25 year design life, bypass diodes and salt mist testing near the coast.
Sizing a system from the customer's electricity bill
The bill carries six numbers that decide system size, and most site visits read only one. How to size a rooftop system before you have measured the roof.
Maharashtra wants a battery on every job above 100 kW
New rooftop solar above 100 kW in Maharashtra must carry storage at half the solar capacity for two hours. How to size it, quote it and explain what it costs.
Shading analysis without guesswork
A parapet, a water tank and a staircase room can cost more generation than a module upgrade recovers. How to measure shade on site and design around it honestly.
DCR and ALMM List-II are not the same rule
Non-DCR modules are not banned outright. Which rule applies to which project, and why the net metering exemption expiring on 31 December 2026 matters.
How to close a rooftop deal on the first site visit
The gap between the site visit and the proposal is where rooftop deals go cold. What to produce on the roof, and what to stop doing back at the office.